1. Technical Field
The present invention relates to a robot system having a function of determining an operator.
2. Description of the Related Art
A series of operations for operating an industrial robot includes an operation such as teaching the robot, which is carried out by an operator within a movable range of the robot. International Standard ISO 10218-2 defining safety standards concerning handling of industrial robots stipulates that only skilled experts should be permitted to carry out maintenance work of the robot. Thus, some operations necessary for operating the industrial robot should not be carried out by unskilled operators in order to prevent serious accidents.
A known robot system is provided with means for limiting functions according to the degree of operator's skill. For example, a magnetic card or a universal serial bus (USB) terminal recording operator's identification information, or a personal identification method using a password has been used. JP 2008-221363 A discloses a robot control system configured to read operator information stored in a radio-frequency identification device (RFID) tag carried by an operator by a RFID tag reader of a teaching pendant. EP 2151726 A discloses a technology for determining an operator by using a memory card, an integrated circuit (IC) card, a USB memory, or a transponder.
However, when the identification card or terminal is lent to others or lost, or when the password is leaked, safety may not be ensured. In addition, once an authorized operator unlocks the restriction, any operator, including unauthorized ones, can then operate the robot to carry out the restricted process.
In recent years, biometric authentication has been introduced as a personal identification method. Use of the biometric information can eliminate a possibility of a loss of the terminal used for the authentication and leakage of information necessary for the authentication. For example, JP 2007-249466 A discloses a controller configured to restrict operator's use of a device based on an image captured by an imaging device. However, the technology disclosed in JP 2007-249466 A is mainly designed to identify those having access rights to personal information and those having no access right in order to protect the personal information, and thus has no relevance to an accident prevention technology when the robot is operated.
Therefore, there is a demand for a robot system capable of ensuring safety by accurately determining an operator who works around a robot.